using System;
using System.Runtime.InteropServices;
using System.Security.Permissions;
using Microsoft.SharePoint;
using Microsoft.SharePoint.Security;
using Microsoft.SharePoint.Administration;
using System.Globalization; 

namespace CustomWorkflowActivitiesProject.Features.CustomWorkflowActivitiesFeature
{
    /// <summary>
    /// This class handles events raised during feature activation, deactivation, installation, uninstallation, and upgrade.
    /// </summary>
    /// <remarks>
    /// The GUID attached to this class may be used during packaging and should not be modified.
    /// </remarks>

    [Guid("a6940608-c6ae-4799-90b2-db6603ca1ad5")]
    public class CustomWorkflowActivitiesFeatureEventReceiver : SPFeatureReceiver
    {
        // Uncomment the method below to handle the event raised after a feature has been activated.

        public override void FeatureActivated(SPFeatureReceiverProperties properties)
        {
            SPWebApplication webapp = (SPWebApplication)properties.Feature.Parent;
            UpdateWebConfig(webapp, true); 
        }


        // Uncomment the method below to handle the event raised before a feature is deactivated.

        public override void FeatureDeactivating(SPFeatureReceiverProperties properties)
        {
            SPWebApplication webapp = (SPWebApplication)properties.Feature.Parent;
            UpdateWebConfig(webapp, false); 
        }


        // Uncomment the method below to handle the event raised after a feature has been installed.

        //public override void FeatureInstalled(SPFeatureReceiverProperties properties)
        //{
        //}


        // Uncomment the method below to handle the event raised before a feature is uninstalled.

        //public override void FeatureUninstalling(SPFeatureReceiverProperties properties)
        //{
        //}

        // Uncomment the method below to handle the event raised when a feature is upgrading.

        //public override void FeatureUpgrading(SPFeatureReceiverProperties properties, string upgradeActionName, System.Collections.Generic.IDictionary<string, string> parameters)
        //{
        //}

        private void UpdateWebConfig(SPWebApplication webApp, bool featureActivated)
        {
            SPWebConfigModification modification = new SPWebConfigModification("authorizedType[@Assembly=\"Custom.Workflow.Activities, Version=1.0.0.0, Culture=neutral, PublicKeyToken=757b1d17624a041f\"][@Namespace=\"CreateActivity\"][@TypeName=\" *\"][@Authorized=\"True\"]", "configuration/System.Workflow.ComponentModel.WorkflowCompiler/authorizedTypes ");
            modification.Owner = "Custom.Workflow.Activities";
            modification.Sequence = 0;
            modification.Type = SPWebConfigModification.SPWebConfigModificationType.EnsureChildNode;
            modification.Value = string.Format(CultureInfo.InvariantCulture, "<authorizedType Assembly=\"{0}\" Namespace=\"{1}\" TypeName=\"{2}\" Authorized=\"{3}\"/>", new object[] { "Custom.Workflow.Activities, Version=1.0.0.0, Culture=neutral, PublicKeyToken=757b1d17624a041f", "Custom.Workflow.Activities", "*", "True" });

            if (featureActivated)
                webApp.WebConfigModifications.Add(modification);
            else
                webApp.WebConfigModifications.Remove(modification);

            SPFarm.Local.Services.GetValue<SPWebService>().ApplyWebConfigModifications();
        } 
    }
}
